Dynamic Needs System

VerifiedSafe

Dynamic needs system that fluctuates over time and drives character behavior. Standard needs include hunger, energy, fun, social, comfort, and bladder, each with decay rates and satisfying actions. Low needs create urgency and can interrupt other activities, with inner voice comments reflecting the character's mental state.

Sby Skills Guide Bot
DevelopmentIntermediate
1506/2/2026
Claude CodeCursorWindsurfCopilotCodex
#needs#simulation#autonomy#behavior#motivations

Recommended for

Our review

This skill enables AI agents to have dynamic needs that fluctuate over time and drive behavior, similar to Sims game characters.

Strengths

  • Creates urgency and realistic behavior
  • Easy to implement with predefined decay rates and effects
  • Inner voice comments (YAML Jazz) add narrative depth
  • Scalable to different characters and contexts

Limitations

  • Only six predefined needs, not easily customizable
  • Decay rates are fixed and do not adapt to context
  • Requires integration with other skills (time, buffs) for full functionality
When to use it

Use this skill when you want to add motivation and decision-making driven by character needs in a simulation.

When not to use it

Do not use this skill if you need complex psychological models or if your application does not involve time progression.

Security analysis

Safe
Quality score92/100

The skill only declares read_file and write_file as allowed tools, and the content is a descriptive specification of a need system, not executable instructions. There is no use of shell commands, network, data exfiltration, or destructive actions.

No concerns found

Examples

Simulate urgent needs
Create a character with the needs skill. Set hunger to 3 and energy to 1. Then simulate one hour. Show the updated inner voice comments.
Explain need effects
Using the needs skill, describe what happens when a character's bladder reaches 0. Include the YAML jazz comment and potential outcomes.
Custom need scenario
With the needs skill, define a scenario where a character's social need is critically low (1) but their fun need is high (8). How do these conflicting needs affect behavior?

name: needs description: Dynamic motivations (Sims-style) — needs fluctuate and drive behavior license: MIT tier: 1 allowed-tools:

  • read_file
  • write_file scale: range: "0-10" meaning: 10: "Fully satisfied" 7-9: "Comfortable" 4-6: "Manageable" 2-3: "Urgent" 0-1: "Critical" standard_needs:
  • hunger
  • energy
  • fun
  • social
  • comfort
  • bladder related: [simulation, society-of-mind, time, buff, character, cat, dog, yaml-jazz, advertisement] tags: [moollm, sims, motives, behavior, autonomy, game]

Needs Skill

Dynamic motivations (Sims-style).

Motto: "Needs drive the story. Low needs create urgency."

Key Concepts

  • Scale — 0-10 (10 = fully satisfied)
  • Decay — Needs decrease over time
  • Urgency — Low needs interrupt other activities
  • Inner voice — YAML Jazz comments reflect mental state

Standard Needs

| Need | Decay | Satisfy | Critical | |------|-------|---------|----------| | Hunger | 2 hours | EAT, DRINK | 2 | | Energy | 3 hours | SLEEP, REST | 2 | | Fun | 4 hours | PLAY, GAMES | 3 | | Social | 6 hours | TALK, hang out | 3 | | Comfort | Situational | Safe place | 4 | | Bladder | 4 hours | Use bathroom | 1 |

Inner Voice (YAML Jazz)

hunger: 7   # Satisfied. No food thoughts.
hunger: 3   # Getting peckish. Is that pie?
hunger: 1   # FOOD. FOOD. FOOD. FOOD.

See Also

  • time — Needs decay over simulation turns
  • buff — Some buffs affect need decay
  • character — Needs stored in character

Full Protocol

Needs Skill — Dynamic Motivations (Sims-Style)

Needs fluctuate over time and drive behavior.

skill: name: needs tier: 1 protocol: NEEDS-AS-MOTIVATION description: | Needs fluctuate over time and drive behavior. Low needs create urgency. Satisfied needs enable other activities. Comments update to reflect inner voice. motto: "Needs drive the story. Low needs create urgency."

SCALE

scale: range: "0-10" meaning: 10: "Fully satisfied" 7-9: "Comfortable" 4-6: "Manageable" 2-3: "Urgent" 0-1: "Critical"

STANDARD NEEDS

standard_needs: hunger: decay_rate: "-1 per 2 hours" satisfy: ["EAT", "DRINK"] low_effects: ["distraction", "irritability", "food fixation"] critical_at: 2

energy: decay_rate: "-1 per 3 hours (faster if Active high)" satisfy: ["SLEEP", "REST", "coffee (temporary)"] low_effects: ["reduced effectiveness", "yawning", "sluggishness"] critical_at: 2

fun: decay_rate: "-1 per 4 hours" satisfy: ["PLAY", "GAMES", "social", "exploration"] low_effects: ["boredom", "restlessness", "seeking novelty"] critical_at: 3

social: decay_rate: "-1 per 6 hours (varies by Outgoing)" satisfy: ["TALK", "hang out", "party"] low_effects: ["loneliness", "craving conversation"] critical_at: 3

comfort: decay_rate: "Situational (environment-dependent)" satisfy: ["Safe location", "familiar place", "cozy setting"] low_effects: ["anxiety", "restlessness", "seeking home"] critical_at: 4

bladder: decay_rate: "-1 per 4 hours" satisfy: ["Use bathroom"] low_effects: ["urgency", "distraction", "accident risk"] critical_at: 1

INNER VOICE (YAML Jazz)

yaml_jazz_comments: description: | Need values have DYNAMIC COMMENTS that serve as inner voice. Comments update when values change!

examples: hunger: high: "hunger: 7 # Satisfied. No food thoughts." medium: "hunger: 5 # Could eat. Not urgent." low: "hunger: 3 # Getting peckish. Is that pie?" critical: "hunger: 1 # FOOD. FOOD. FOOD. FOOD."

energy:
  high: "energy: 8  # Wide awake. Let's DO things."
  medium: "energy: 5  # Fine. Maybe coffee later."
  low: "energy: 2  # So tired. Everything is hard."
  critical: "energy: 1  # Can't... keep... eyes..."
  
social:
  high: "social: 9  # People are great. I love everyone."
  medium: "social: 5  # Could use a chat."
  low: "social: 2  # Is anyone there? Hello?"

DECAY

decay: timing: "Needs decay over simulation turns" factors: - "Base decay rate" - "Personality traits (Active, Outgoing)" - "Current location effects" - "Active buffs" - "Dribble food to bladder"

SATISFACTION

satisfaction: actions: "Most needs satisfied by specific actions" locations: "Some locations satisfy needs passively (home, pub)" items: "Some items satisfy needs (food, bed)" social: "Interactions can satisfy social need"

CRITICAL NEEDS

critical_needs: description: | When a need hits critical level, behavior changes: - Inner voice becomes URGENT - Other activities interrupted - May trigger autonomous actions

example: | hunger: 1 # I CAN'T THINK ABOUT ANYTHING ELSE # IS THERE FOOD? WHERE IS FOOD? # [Character may abandon current task to find food]

integrates_with:

  • skill: character how: "Needs stored in character state"
  • skill: time how: "Needs decay over simulation turns"
  • skill: buff how: "Some buffs affect need decay rates"
  • skill: room how: "Locations can satisfy needs"
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